To call Ernesto "Che" Guevara a polarizing figure is an understatement, and to call his politics complicated is an even larger one.
It has a lot to do with Che's politics and upbringing versus his application of said tactics on the battlefield.
He was born into a wealthy family and attended medical school. While there, he took a motorcycle tour around Central/South America, where he witnessed instances of horrible poverty, which he blamed on capitalist ideals. It was shortly after that he met Fidel Castro, and went from being a doctor to being a revolutionary leader. This is where Che goes into a more controversial role. While he did seek to aid the people, he also was responsible for organizing trials against Batista supporters, and had executed an estimated 500 supporters. He is also largely responsible for Cuba's alliance with Russia, and even helped to get the missiles into Cuba, which would eventually cause the Cuban Missile Crisis. Guevara was very outspoken in believing that Cuba should launch an attack against the United States, an idea which Castro ultimately rejected and would also lead to Guevara's exile from Cuba. ^[1]
To many, Che was a hero to the people. He outlines very well how important it is to be seen as a "Freedom Fighter" and not a "Terrorist" in his book Guerrilla Warfare. He was also largely responsible for the increase in literacy in Cuba as well as supporting the building of universities.
He stresses not attacking civilians, but instead gaining their support, as well as paying back debts owed to civilians that helped finance revolutionary movements as soon as possible. He was reportedly quite popular among his soldiers, however he punished traitors and deserters with extreme ferocity. ^[2]
French historian Pascal Fontaine says about Che Guevara:
“Just as Jacobin Paris had Louis Antoine de Saint-Just, revolutionary Havana had Che Guevara, a Latin American version of Nechaev, the nineteenth century nihilist terrorist who inspired Dostoevsky’s The Devils. As Guevara wrote to a friend in 1957, ‘My ideological training means that I am one of those people who believe that the solution to the world’s problems is to be found behind the Iron Curtain.’…He was a great admirer of the Cultural Revolution [in China]. According to Regis Debray, ‘It was he and not Fidel who in 1960 invented Cuba’s first corrective work camp,’ or what the Americans would call a slave labor camp and the Russians called the gulag.” ^[3]
It's this polarization that causes such mixed views on Che Guevara. Not only was he an advocate of "death squads", basically state sponsored assassins, he also helped establish slave labor camps and was closely allied with the Soviet Union. However, with every insurgent conflict, one man's terrorist is another man's freedom fighter.
I might direct you to this discussion of Che and his place in popular culture by /u/ainrialai.
As an add on question to the thread. Do historians of the subject view George Plimtons accounts of watching Che's firing squads with Hemingway as accurate or trust worthy?